Yes, it has undergone revisions since which caused function name mismatch (EDIT: fixed). The execute_activity there uses start_to_close_timeout which is per attempt and will retry forever by default (customizable).

This is more of a primer on the Python part of Temporal rather than an explanation of all Temporal concepts in depth. Definitely would recommend reading the fundamental docs at https://docs.temporal.io/encyclopedia/. For more exact samples, see https://github.com/temporalio/samples-python.